Help for fossil ID

[Timtile]

We found this today while sifting for shark teath at Caspersen Beach Fla. It is 1 inch long and 5/8s wide. We think it’s really beautiful, and any help identifying it would be greatly appreciated!

[hemipristis]

Porcupinefish jaw

[citronkitten]

I used this website before going on a fossil hunting trip on the Peace River, Arcadia, Fl. Nice images and not an overload of information. There's a picture of a burrfish mouthpiece that closely corresponds to yours. 
 

https://www.fossilguy.com/sites/peace-river/peace-river-fossils.htm#porcupine